Re: Add LZ4 compression in pg_dump

On Wed, Apr 12, 2023 at 07:53:53PM -0500, Justin Pryzby wrote:
> I doubt it - in the !HAVE_LIBZ case, it's currently an "if" statement
> with nothing but a comment, which isn't a problem.
>
> I think the only issue with an empty "if" is when you have no braces,
> like:
>
> if (...)
> #if ...
> something;
> #endif
>
> // problem here //

(My apologies for the late reply.)

Still it could be easily messed up, and that's not a style that
really exists in the tree, either, because there are always #else
blocks set up in such cases. Another part that makes me a bit
uncomfortable is that we would still call twice
parse_compress_specification(), something that should not happen but
we are doing so on HEAD because the default compression_algorithm_str
is "none" and we want to enforce "gzip" for custom and directory
formats when building with zlib.

What about just moving this block a bit up, just before the
compression spec parsing, then? If we set compression_algorithm_str,
the specification is compiled with the expected default, once instead
of twice.
--
Michael